Toptsidis said all OPAP retail outlets were closed and called on the government to repeal the tax.

"The participation rate is close to 100 percent," he said, adding that agents had also seized OPAP's data processing centers in Athens and Thessaloniki, the country's two biggest cities. He said the new tax would discourage players from wagering their profits in OPAP's flagship games Stihima and Kino.